Obstetrical tractor.



H. HANSON.

OBSTETRICAL TRACTOR.

APPLICATION FILED MAR. a. 1915.

Patented Aug. 31, 1915.

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- ime A HENRY-HANSON, or Ei/iraoNsMnvNnsoTa' ,OBYSTETRICAL TIt-AGTOR I 1 To all whom it may concern Be it known that I, HnNRY'HA so a citizen of the United States, residing at Emmons, in the county of Freeborn, $tate of Minnesota, have invented certain new and useful Improvements in Obstetrical Tractors; and I do hereby declare the following to be a full, clear,'and exact description of the inventiom such as will enable othersv skilled in the artto which it appertains to.

make and use the same.

This invention relates to improvements in obstetrical instruments and particularly to a tractor used in veterinary obstetrical surgery.

The principal object of the invention is to provide a device of this character which is capable of adjusting itself to objects having circular or irregular outlines.

Another object is to provide a device of this character which is of such construction that there will be no projections to injure the parts when the instrument is inserted.

Other objects and advantages will be apparent from the following description when taken in connection with the accompanying drawing.

In the drawing: Figure 1 is a perspective view of the device in open position and partly broken away, Fig. 2 is a side elevation of the device in closed position, Fig. 3 is a vertical longitudinal sectional view through the device in open position, and

Fig. 4c is an end view of the device in open position, the outlines being circular.

Referring particularly to the accompanying drawing, 10 represents a shank on one end of which is a suitable hand grip 11. Carried by the other end of the shank are a plurality of spring aws '12, the outer ends of which are formed with eyes 13. Through the shank and handle is formed a bore 14, and slidable through this bore is a rod 15 provided with a plurality of ratchet teeth 16. Pivotally mounted on the handle is a thumb lever 17, the thumb engaging end of which is pressed upwardly by a double leaf spring 18. The other end carries a pivotally connected pawl 19 which works through an opening 20 formed in the handle. The inner end of this pawl engages with the ratchet teeth of the rod 15. The outer end of the rod is formed with an eye 21. An endless cord is passed through the eyes of the jaws 12 and the remaining portion brought down alongside of one of the jaws and is passed Specification ofLetters Patent.

lil ltOllgll ltlle eye of the rod. The normal tendency of the jaws isjto expand into Patented Aug. 31, 1915. j Application a ea'i ra h 8,19,15,, SerialNoL12,9O3.. i i i by graspingthe hand grip '15" carried thereby, thefintermediate portion of thefcord which is passed through the eye 21 "will be drawn into the shank, thus resulting in, the contracting of the ring of the cord which passes through the eyes of the jaws and drawing the outer ends of the jaws together.

IVhen the device is engaged with an object having a circular contour all of the spring jaws will be drawn equally inward so as to bear against all points around the object. Should an object of irregular outline be operated upon, all of the jaws will not touch the surface of the object. In this case, by reason of the fact that the endless cord passes through the eye of the shank, one of the portions of the cord between the outer. end of the spring jaw, and the end of the shank will be drawn at a greater speed than the other portion so that this portion of the cord will slide through the eye 21 of the rod 15. This is clearly illustrated in the perspective View of Fig. 1, in which the jaws 12 and 12 are drawn inward to a greater degree than the other jaws.

From the foregoing it will readily be seen that I have provided an extremely simple and efficient device of this character and one which is readily capable of adjustment to an irregular object.

Particular attention is called to the fact that the corddraws the jaws inward without the aid of any extra device and that the pawl and ratchet device holds the jaws in such contracted position. By grasping the handle 11, after the jaws have been firmly gripped around the fetus, the same can be easily withdrawn as will be readily understood.

It will further be noted that by reason of the fact that all of the operating mechanism is within the jaws and that there are no projections or parts to produce a pinching act1on, no injury can result from the away from each ether, a longitudinally slidable rod disposed through the shank and provided With an eye at the outer end and a hand grip adjacent the handle of the shank, said rod being provided with a plurality of ratchet teeth, a spring pressed pawl carried by the handle and engageable with the teeth through the handle, the outer ends of the jaws being provided With eyes, and an end less cord engaged through the eyes of the jaws and through the eye of the rod.

2. An obstetrical tractor comprising a shank, normally open fetus grasping jaws carried by one end of the shank and provided with eyes at their outer ends, an operating rod slidable through the shank and provided with an eye at its outer end, and an endless cord slidably engaged through the v outer ends of the jaws and the eye of the rod whereby when an irregular object is grasped by the jaws the portion of the cord I which passes through the eye of the rod will HENRY HANSON.

Witnesses:

E. S. DARs'r, H. M. LAWRENCE.

Copiesof this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. 

